Resumen de The Complexometric Determination of Calcium and Magnesium in Limestone Using a Laser Photometer for Endpoint Identification
Daniel M. Mossman, Robert G. Kooser, Lawrence E. Welch
An alteration of the classic complexometric titration of calcium and magnesium with EDTA was made to incorporate a laser photometer for endpoint detection. The photometer utilized a He-Ne laser, which allowed the red to blue transition of the calgamite indicator to be followed by monitoring the change in beam absorbance. A photodiode and an inexpensive computer interface were used to record the intensity of the transmitted laser beam as a function of time. This method makes the experiment much more accessible for students suffering from color blindness.
